The main objective of the proposed research is to assess the potential for using oxidants produced[unreadable] during the corrosion of granular and nanoparticulate zero-valent iron (ZVI) by oxygen to remediate[unreadable] contaminated groundwater and soil. This objective will be realized by studying the reaction mechanisms[unreadable] involved in oxidant production and contaminant transformation and the efficiency of potential treatment[unreadable] methods under conditions similar to those that are likely to be employed in treatment systems. The overall[unreadable] hypothesis that we aim to test is that the oxidative ZVI system offers a practical, cost-effective means of[unreadable] remediating contaminants that have the greatest impact on human health at Superfund sites.[unreadable] Our investigation of the reaction mechanisms will focus on the role of solution chemistry and surface[unreadable] structure on the rate of contaminant transformation. To gain insight into the processes occurring on or[unreadable] near ZVI surfaces, chemical processes occurring in the solution phase will be measured in conjunction with[unreadable] studies conducted using techniques designed to probe the surface, such as potentiometry, surfaceenhanced[unreadable] Raman spectroscopy and electrochemical quartz microbalance methods.[unreadable] Our investigation of the potential applications of the oxidative ZVI system to contaminant remediation[unreadable] will focus on permeable reactive barriers and water infiltration systems used to treat organic contaminants[unreadable] and drinking water treatment systems used to remove arsenic. These studies will extend the research in[unreadable] oxidant formation mechanisms to account for the effect of oxide coatings on the ZVI surfaces on[unreadable] contaminant oxidation rates and transport of contaminants to and from the corroding iron surfaces.[unreadable] This research has the potential to provide innovative and cost-effective ways of removing contaminants[unreadable] from groundwater and drinking water that are difficult or expensive to treat by conventional methods. The[unreadable] development of these technologies could reduce human exposure to organic and inorganic contaminants[unreadable] of concern.